Microphone preamplifiers are difficult to review because they just lie there and do nothing. They just take your microphone signal and amplify it up to some usable recording level so you can use up as many bits as possible. Then you forget about them.

A few months ago I had the opportunity to use the new TRUE Audio Systems Precision 8 microphone preamp. The feature that initially interested me was the built-in instrument interface (on channels 7 and 8), or "direct box," that enabled you to plug an electric guitar or keyboard directly into the mic preamp without an additional box. A professional balanced microphone usually has an impedance matching requirement of around 150 ohms, while a guitar pickup or synthesizer requires an impedance match in the neighborhood of 10,000 ohms. The reason I mention this is because I often see synthesizers plugged directly into a mic preamp without a direct box. The sonic result is a thin-sounding instrument caused by impedance mismatch. The Precision 8 mic preamp prevents such occurrences.

The next feature that I liked was the eight mic preamps in a single rack space. It fits comfortably in my Pro Tools rack for direct recording from microphone to hard disk. Each input has a five-segment meter on the front panel to monitor levels. There is a master control to set the clipping reference level to match the recording device you are feeding, and a separate phantom power switch for each mic preamp. Some condenser microphones with their own power supplies can become very noisy when you are unable to turn off the phantom power at the mic preamp.

The input connections on the rear panel are XLR. Channels 7 and 8 will also accept 1/4-inch plugs for the direct instrument interface. The output connections are either 1/4-inch balanced phone plugs or XLR connectors on a snake that is attached to the rear panel by a DB25 connector. (There isn’t physically enough room for eight additional output XLRs on a single-space chassis.)

In Session
The first project I used the 8-channel preamp on was drums for the Pancho Sanchez Band. The transient response was amazing and the crystal clarity was just what I was looking for. The sound of this mic preamp rivals that of microphone preamps costing three to five times as much money. The first two channels of the preamp are set up for M-S decoding. I used the M-S configuration for the drum overheads, using a cardioid mic for the Mid signal and a bidirectional (figure-eight pattern) mic for the Side signal. I could control the stereo spread of the overheads using the M-S controls on the front of the unit.

The results I got with drum recording were so good that I used it for a Les McCann recording, a Robben Ford project, and a Brenda Russell recording. The drum sound on all of these recordings sparkled.

Not to be content with only a good drum sound, I powered up the mic preamp for a Tower of Power horn section session. Wow! (Can I say that in a family-oriented magazine?) During playback the horn guys commented on the great horn sound and asked what kind of EQ I was using. I said wasn’t using any EQ at all. I was recording from microphone to Precision 8 mic preamp to digital machine, period. Everyone was impressed, including me. To check out the direct instrument feature I recorded Don Grusin’s synths on a couple of songs. The keyboard sounds were "perfect." No EQ, just punch Record and go.

Conclusion
The only thing that I would like to see added to this preamp is detented knobs for mic level. When someone walks up to my rack and says, "What’s this?" they inevitably bump a knob that I had just tweaked to perfection. Discounting that comment as a personal whim, I could find absolutely nothing else lacking with the Precision 8. The twin-servo circuit design of the Precision 8 eliminates almost all of the capacitors in the audio path, providing a frequency response of 1 Hz to 500 kHz. Distortion values are less than .008 percent and crosstalk between channels is less than –130 dB. The TRUE Audio Systems Precision 8 is a nice piece of engineering.

EQ Lab Report